Drill-gage.



0. J. FAIRGHILD.

DRILL GAGE. APPLIOATION FILED NOV. 30, 1909.

Patented N ov. 7, 1911.

UWE/won OREN J. FAIRCHILD, OF BINGHAMTON, NEW YORK.

DRILL-GAGE.

Speccaton of Letters Patent.

Application led November 30, 1909.

Patented Nov. "1', 1911.

Serial No. 530,685.

To all whom it' may concern:

Be it known that I, OREN J. FAIRGHILD, a citizen of the United States, residing at Binghamton, in the county of Broome and State of New York, have invented certain new and useful Improvements in Drill- Gages, of which the following is a specication, reference being had therein to the accompanying drawing.

This invention relates to tool gages, and has for its object the provision of means for conveniently testing the correctness of the form and angles of the cutting edges, and the position of the point, of a drill, to the end that its maximum cutting service, coupled with accuracy of work, may be obtained.

Briey stated, the invention consists of a frame, forming a receptacle or guide for holding the drill in correct relative position to the gage proper, which is formed -into a slide so mounted upon said frame as to admit of convenient adjustment to correspond to various sizes of drills, and thereby to automatically indicate in each case the proper speed of drill being gaged. Means are provided for securing said slide to the required adjustment.

Referring to the accompanying drawings: Figure l is an elevation of the gaging device complete, upon which is shown in dotted lines a drill in proper position for testing. Fig. 2 shows in perspective the slide and locking means separated from the frame. Fig. 3 is a cross section on line 3-3 of frame A.

In the drawings, A is a frame provided with a straight member grooved at A to receive a drill for testing, also provided with an angular member A10 drilled and slotted through at A2, to receive the slide B and the slotted clamping pin C. These parts are shown separately in Fig. 2, and assembled in Fig. 1. In the latter figure cheek plates a and a2 are shown extending in both directions from the post a, and bearing tabulated indications of the proper speeds of different sizes of drills in diierent materials, such as iron and steel. The slide B has at one end gaging edges B', at the other end a caliper jaw B3, and projecting from its lower edge a trigger B2. Cut in the upper edge are index marks B4 for the respective tables on the plates a and a2, showing the speeds at which the drills gaged should be run, in steel and in iron respectively. The gaging edges B are cut at such an angle as to fitl the point of a drill when properly ground for its work. The diameter being engaged by the jaws A3, B3, the edges .B then serve as a gage for the point.

The operation of my device is as follows: It is assembled by placing the slide in the slot A2 with the trigger B2 projecting through into the middle of the frame; the slotted pin C isv then slipped over the body of the slide through the post a, with its threaded end' c projecting within the frame, to receive the thumb nut D. With this nut loose, the -slide is then free to move back and forth. With the instrument in the left hand, the nut is manipulated by the thumb and index linger, while another finger within the trigger B2 adjusts the slide upon a drill to be ground or tested, this being held by the right hand between the jaws A3 and B3. The thumb nut D then being tightened, the gage is set to lit a perfect drill of that size and indicate its proper speed.

I am aware that sundry changes in detail may be made in the design of my gage without departing from the spirit of my invention and I wish it distinctly understood that I contemplate all such changes as fairly fall within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. A drill gage comprising a body carrying a support and a caliper jaw, and a movable member adapted to be set with reference to said caliper jaw to determine the diameter of a drill to be gaged, said movable member carrying a jaw with surfaces formed at an angle adapted when the member is set, to indicate the proper center and angle of grinding for the point of said drill, together with means controlled in the movement of said member to indicate proper speeds for different drill dimensions.

2. A drill gage comprising a triangular body grooved along one side to receive and hold the drill to be gaged, a fixed caliper jaw on the body at the angle opposite to the grooved side, and a slide adapted to move along a second side, with a caliper jaw at one end adapted to coperate with the fixed jaw on the frame, and a gage edge at the other end adapted to overlie the point of the drill to be gaged.

3. A drill gage comprising a frame, a

straight guide on said frame adapted to receive a drill, a slide member and a coperating abutment constituting a caliper oarried obliquely to the said guide, and a aw carried on the slide member beyond the end of the guide, and having meeting surfaces ground at the proper angle and meeting at the proper point to fit the point of a drill in the guide when the caliper is set for the diameter of said drill.

4. A drill gage comprising a frame, a straight guide on said frame adapted to receive a drill, a slide member and a coperating abutment constituting a caliper carried obliquely to the said guide, and a jaw carried on the slide member beyond the end of the guide, and having meeting surfaces ground at the proper angle and meeting at the proper point to fit the point of a drill in the guide When the caliper is set for the diameter of said drill, together with means extending into the frame for moving the slide.

5. A drill gage comprising a frame, a straight guide on said frame adapted to receive a drill, a slide member and a coperating abutment constituting a caliper carried obliquely to the said guide, and a jaw carried on the slide member beyond the end of the guide, and having meeting surfaces ground at the proper angle and meeting at the proper point to fit the point of a drill in the guide when the caliper is set for the diameter of said drill, together With means eX- tending into the frame for moving the slide, and locking means for the slide When adjusted.

6. A drill gage having a substantially triangular frame, With a straight guide on one side, and a slide member on another side carrying at one end a jaw ground to fit drill points being gaged, and at the other end a caliper device, the angle of the Slide and the guide being such that When the slide is set to the diameter of a drill, the center point and edges of the gage jaw will indicate the proper center point and cutting angle of the drill.

In testimony whereof I affix my signature in presence of two witnesses.

@REN J. FAIRCHILD. l/Vitnesses:

HARRY C. PERKINS, CHARLES G. BLAKESLEE.

Copies of this patent may be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C. 

